I own a csi stock sizing 56cm seat and top tube which fits like a glove.I am having trouble with the sizing for a bianchi it looks like i need a 59cm bianchi to get a 56cm top tube is this right if so is standover going to be an issue as well as wheelbase.

re: Bianchi sizing?

JohnnyPMay 28, 2001 7:07 PM

Acording to my book, all the 59cm (C-T) Bianchis have toptubes longer than 56 cm. Some of the 57cm models have 56cm toptubes.You reading the right eyechart? Isn't the CSI measured c-c?

re: Bianchi sizing?

bianchi boyMay 28, 2001 7:27 PM

Unless the dimensions have changed with the new sloping top tube designs, a Bianchi with a 57 cm seat tube would have a 56 cm top tube. Bianchi measures their seat tubes center to the TOP of the seat tube. Measured center-to-center, they are quite a bit smaller. For instance, my 57 cm (c-t) Bianchi Alloro measures about 54 cm c-t-c. The top tube is 56 cm c-t-c. According to manual that came with my bike, a 59 cm Bianchi would have a 57.5 cm top tube for the Megapro, XL and Boron frames. For the Alloro, Daytona, Veloce, Giro and Campione frames, a 59 cm seat tube would have a 57 cm top tube. For all of these frames, the 57 cm's measure 56 cm for the top tube.

If you are looking at a new frame with the sloping top tubes, I would check the www.bianchiusa.com website. For each frame, you can check the specifications and geometries on their website.

For what it's worth, my 57 cm Bianchi fits more like a 55 cm, in my book. The standover height is at least a half-inch lower than the officials specs. If you have trouble riding with handlebars much lower than the saddle, be cautious about getting a newer Bianchi frame. With the compact frame design, the headtubes are quite short and it is hard getting much extension from the steerer tube without using a lot of spacers.